PROJECT SUMMARY A major challenge for precision medicine research is including historically under-represented groups in numbers sufficient to ensure statistically valid inferences of the influence of relevant risk factors, including genetic contributions to disease risk. Precision medicine researchers have recognized the critical need to enhance diversity and have implemented a wide variety of approaches to achieve this. All such approaches, however, are shaped by stakeholders? understandings of what kinds of diversity matter, the local logistical constraints under which precision medicine research is actually being conducted, and the responses of communities to those approaches. Investigating these complex factors from the perspectives of multiple stakeholders in precision medicine research will be essential to effectively address longstanding inequities in genomic and related forms of precision medicine research. This application seeks to take advantage of the current proliferation of diversity and inclusion practices to study their heterogeneity, commonalities, and effects on diversifying participation in precision medicine research. We will determine through in-depth analyses of PMR studies how concepts such as definitions of diversity (e.g. genetic ancestry markers, self-reported race and ethnicity) impact practices such as retention, engagement, and return of results. Taking a lifecourse perspective to research relationships, we aim to assess how approaches towards diversity and inclusion are managed in tandem with other research goals and the implications of specific trade-offs that result. To achieve our study objectives, we will fulfill the following aims: (1) identify scientific and sociopolitical justifications for goals of inclusion and conceptual definitions of diversity in precision medicine research; (2) determine how scientific, social and technical factors influence the operationalization of diversity and implementation of inclusion in precision medicine research; and (3) engage stakeholders to create data-informed guidance that describes the strengths and weaknesses of diversity and inclusion decisions and practices in precision medicine research.